Thermoplastic polyester series resin foamed material and production process thereof

ABSTRACT

A thermoplastic polyester series foamed material having a thickness of at least 3 mm and an apparent density of from 0.05 to 0.7 g/cm&lt;3&gt; is diclosed, wherein the crystallinity of the resin in the surface portion within 0.5 mm from the surface of the foamed material is not more than 30% and at least 1% lower than the crystallinity of the resin in the central portion of the foamed material.



